A server that does not have a keyboard, mouse, or monitor hooked to it is known as a headless server. These are commonly used because they can be installed into a data center, data closet, or other location where they will perform their specific functions with little to no interaction from an administrator. When everything is working properly, any setup and configuration processes can be done by accessing the server remotely through the network. This is often done through a management or console connection.
Servers are designed to perform specific functions for users that connect to them. If you find that you cannot remotely connect to the server in order to troubleshoot problems, the first thing you should typically do is simply reboot or power fail the server. Depending on the model of the server, this can either be done by pressing and holding the power button until it turns off, or simply unplugging the server and plugging it back in (note that many servers have dual power supplies so you will need to unplug both).
If you lose your ability to manage the server remotely and rebooting does not restore this ability, however, you can access the server by physically plugging in a portable monitor and begin troubleshooting the issue. Troubleshooting a headless server using a portable monitor is something that anyone providing IT support needs to learn.
Options for Connecting a Portable Monitor
If you are unable to access your headless server remotely, you need to connect a portable monitor (and likely a keyboard and mouse as well) so you can see what is wrong with it. Different server models will have different options for connecting your portable monitor. The following are some of the most common options available:
- Individual Ports – Some headless servers will have a separate port for the monitor, the keyboard, and the mouse. Keep in mind that there are quite a few different styles of ports for monitors, so make sure you have the right one or an adapter to connect to it.
- USB Connection – You may find that your server has USB ports that are able to be used to connect a monitor and input devices for troubleshooting. With this option you can either use an adapter to connect the monitor, keyboard, and mouse to the USB port or you can plug each device into a separate USB port if there are enough.
- KVM Port – It is quite common for a headless server to have what is called a KVM port, which stands for keyboard, video, mouse. If you want to use this port, you will need to have all three devices go into an adapter, which can then plug into the server’s KVM port.
If you have a lot of headless servers, you may want to set up a ‘crash cart’ in your data center. This crash cart would have a portable monitor, keyboard, and mouse on it so that you can bring it right to the server you need to troubleshoot. If you don’t have a lot of these devices, you can typically just grab a monitor, keyboard, and mouse from another computer in the office and connect it as needed.
Troubleshooting Once Connected
Once you have your portable monitor and input devices connected directly to the headless server, you can begin to troubleshoot the problems like you normally would. In most cases, you will be able to see your server boot up on the portable monitor so you can watch for errors. Each type of server will also have its own list of error logs, troubleshooting tools, and other things that can help you to identify the cause of the problems you are experiencing.
In most cases, you will want to start by looking for problems related to network connectivity. This is because when you cannot access the server remotely, it is typically due to a problem in this area. One of the first things that most headless servers will load is the ability for management connections to access the system. If it never gets to that point, it will generally be caused by the network connectivity issues. For this same reason, you may also want to check to confirm that your network cables (typically a cat-6 cable for management connections, but not always) are plugged in correctly and not damaged in any way. If you have a network cable tester, it is worth verifying that the cabling is not your issue.
If you do not find anything wrong with the network connectivity, you will want to continue troubleshooting the issues as you would any other server. Look for error messages or other problems that can give you a clue as to where the problem exists. If necessary, reach out to the manufacturer of the server to see if they can provide you with insights as to where the problem exists.
If you find that your issue is caused by a hardware problem, make sure that you have it repaired or replaced by an authorized technician. If you attempt to open or repair a headless server on your own, it will typically void your warranty. Of course, if you have an authorized repair technician on staff, they will be able to perform this type of task.
Configuring Your Headless Server Correctly
Once you solve the issue with your headless server, you will want to make sure that everything is setup and configured correctly to make troubleshooting in the future easier. If you haven’t already, make sure you have both management and console network connections in place. This will allow you to connect to the server remotely to perform most troubleshooting that is needed. As mentioned above, these types of connections are not foolproof as they do rely on a good network connection, but for the majority of software and operating system problems, they can be used to find a solution. Once in place, you will find that troubleshooting your server is faster and easier than before.